Author Topic: Downtown 300I - Throttle situation  (Read 778 times)

mooselooseinodumga

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Downtown 300I - Throttle situation
« on: April 21, 2015, 01:52:30 AM »
I own a Kymco 2012 Downtown 300I. Recently, my vehicle got to where when I slowed down to apply brakes at either a stop sign or red light, it wanted to keep going and not stop. I took it to my dealer. They had to order both an Air Filter and a Sensor that had gone out. They replaced both parts. Unfortunately, the problem continued. My dealer told me they had made some calls  and the service technician did everything they suggested. I'm now hearing that replacing a couple of parts involving the throttle could help my situation. I don't really want to be tied down with financing on a new vehicle; I would like very much to keep my Downtown 300I; it's one of the best vehicles I have ever had. Will replacing the throttle parts help at all here? What else can I do at this point? I would appreciate some answers. I'm simply not ready to give up on this vehicle. The vehicle has around 36,000 total miles. I've had it since January 16, 2012. Any help, advice appreciated!

CROSSBOLT

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Re: Downtown 300I - Throttle situation
« Reply #1 on: April 22, 2015, 04:37:05 PM »
Moose, your dealer has NOT read the service manual and he is added to my list of Kymco dealers that do NOT know their product (and other really inappropriate descriptions....). You / the tech MUST initialize, repeat, INITIALIZE anytime the TPS, ISC and anything are replaced in the EFI system. This is an animal that you cannot, repeat, CANNOT, just throw parts on to "fix" problems. Initialize is: run/stop switch in RUN; key OFF; open throttle to stop; key ON (DO NOT START); after 8 seconds, throttle closed, key OFF; Then start engine normally, idle should be 1600 rpm +/- 100 rpm. Ride around awhile to see if throttle behaves normally. If not, do INITIALIZE again (Bill Gates fix, kinda). Your "dealer" could have done this up front and would not have had to do the parts thing most likely. Since the parts did not fix the problem I am led to believe that initialize would have fixed it originally. I have had to do this on my DT300i several times since new 'cause of goofy idle. Runs really well and has done so for a long time since last initialize.

Karl

PS: Does your "dealer" even have a Kymco analyzer?
« Last Edit: April 24, 2015, 08:50:02 PM by CROSSBOLT »
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

BettinANDlosing

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Re: Downtown 300I - Throttle situation
« Reply #2 on: April 22, 2015, 06:42:28 PM »
The throttle cable itself might be sticking.
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

CROSSBOLT

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Re: Downtown 300I - Throttle situation
« Reply #3 on: April 22, 2015, 07:11:35 PM »
B&L has a good point. When hearing hoofbeats look for horses before you look for zebras! My DT and wife's GTi300 have two cables to the throttle: one pulls it open and one pulls it closed plus a return spring at the throttle body.

Karl
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

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